I just bought a used lss the previous owner changed the stock speaker to a v30 . I would like to put the c90 back in it . Can someone tell me what impedancd speaker goes in it 16 or 8 ohm ? The v 30 is a 16 ohm .I know very little about class a amps and the fact that the speaker out has wattage ratings instead of impedance ratings baffles me .